The drive device is used to drive the motor vehicle, and thus it also serves to provide a torque for driving the motor vehicle. The drive device is provided with a plurality of drive units, wherein the internal combustion engine represents a first drive unit of the drive units, the second electric machine represents a second drive unit of the drive units, and the second electric machine represents a third drive unit of the drive units. It goes without saying that drive units of another type could be also used instead of the internal combustion engine, the first electric machine and the second electric machine.
When the internal combustion engine is started, it must be first brought to a minimum rotational speed, for example from the standstill state. The minimum rotational speed in this case preferably corresponds to a number of rotations at which the internal combustion engine can be operated independently, which is to say without operating the internal combustion engine by applying an external torque. Based on this minimum rotational speed, the internal combustion engine is then further accelerated and its rotational speed can be further increased automatically.
The first electric machine is used to bring along the internal combustion engine and to this extent also to provide an external torque. For this purpose, the internal combustion engine or its drive shaft can be coupled to the first electric machine, or to its drive shaft, by means of the first clutch. This means that the operating connection between the internal combustion engine and the first electric machine is interrupted in the first switching position of the first clutch, while at least a second switching position is at least partially produced.
It is particularly preferred when the internal combustion machine and the first electric machine are rigidly coupled to one another in the second switching position of the first clutch. With the aid of the first clutch, the drive shaft of the internal combustion engine can be connected or coupled to the first electrical machine, wherein both of these terms are being used synonymously in the context of this description. Alternatively or additionally, the internal combustion engine can be coupled to the first electric machine via the second clutch, wherein blocking of the planetary gear may be necessary.
Furthermore, the first electric machine, or its drive shaft, is connected via the transmission device to the drive shaft of the drive device. The drive device can be for example a multi-gear transmission or a manual transmission, by means of which the transmission ratio can be selected from a plurality of transmission ratios so that the transmission ratio between the internal combustion engine and the output shaft can be adjusted.
For example, the transmission device can be provided in the form of an automatic transmission that has several gears, for instance at least four, at least five, at least six, at least seven or at least eight forward driving gears. However, such a configuration requires on the one hand a large amount of space in the motor vehicle, and on the other hand it is also complicated to implement.
It is therefore the object of the invention to propose a drive device for a motor vehicle which has advantages of known drive devices, in particular because it enables a more flexible operation of the drive device, while at the same time it also enables a significantly reduced amount of installation space.